Optically and fluidically enhanced in vitro diagnostic test chamber

ABSTRACT

An enclosed chamber is used in a system for screening of a liquid specimen through binding assays. The enclosed chamber includes an inlet, an outlet, and a plurality of discrete reactant containing wells communicated by a common reagent flow path between the inlet and the outlet. A transparent member or coverslip defines on an inside thereof the plurality of wells. Each well has a bottom for receiving an allergent/antigen/reactant, which emits light upon reacting. The coverslip can optionally define at least one lens at each well. A bottom encloses the plurality of wells and defines between the inlet and the outlet a common reagent flow path between the inlet and the outlet. This bottom defines for each of the plurality of wells a flow-diverting member. An opaque partition is disclosed for surrounding the individual lenses and generally isolating the light path from each well.

RELATED PATENT APPLICATION

This application claims priority from US Provisional Patent ApplicationSer. No. 60/191,324 filed Mar. 21, 2000 and entitled OPTICALLY ANDFLUIDICALLY ENHANCED IN VITRO DIAGNOSTIC TEST CHAMBER by the inventorsherein.

This invention relates to an apparatus and method for use in thediagnostic analysis of a liquid specimen through binding assays. Moreparticularly, an optically and fluidically enhanced in vitro diagnostictest chamber and process of chamber utilization is disclosed over theapparatus and method disclosed in Sell et al U.S. Pat. No. 4,567,149issued Jan. 28, 1986.

BACKGROUND OF THE INVENTION

In Sell et al U.S. Pat. No. 4,567,149 issued Jan. 28, 1986, an apparatusand a related method for use in the diagnostic analysis of a liquidspecimen through binding assays was disclosed. The apparatus included arigid body and a plurality of elongated threads, sometimes also referredto as filaments and/or strips, each coated with a binding assaycomponent and supported on the body in spaced relationship forsimultaneous contact with a liquid specimen. The plurality of elongatedthreads was positioned across an elongated well formed in the rigidbody, generally transverse to the well's longitudinal axis. Atransparent member, hereafter referred to as a coverslip, secured to therigid body enclosed the elongated well between an inlet and an outletalong a common reagent flow path from inlet to outlet. The threads wereprotected during handling of the apparatus.

In use, a specific volume of the liquid specimen could be confined andisolated in the well, where it can incubate with the threads. Theapparatus of the invention was particularly suited for allergyscreening, with each elongated thread being a cotton thread coated witha specific allergen.

The rigid body used in Sell et al preferably was formed of plastic andincluded a flat land surrounding the elongated well. The thread wastensioned across the well, from lands on opposite sides of the well. Thecoverslip overlaid the threads and was secured to the lands on oppositesides of the well. To facilitate insertion of various liquids into thewell, including the liquid specimen to be tested, suitable washingsolutions, and a labeled antibody solution, the rigid body included aport at each end of the elongated well. The apparatus further included apipette projection in alignment with the port located at one end of thewell.

The coverslip preferably included a thin plastic sheet in direct contactwith the land of the rigid body. The coverslip had an overlaying a silkscreen having a series of parallel narrow apertures, each aligned with aseparate one of the cotton threads. The silk screen optimizes themeasuring of the reaction of each cotton thread by reducing theinterfering effects of adjacent threads. The coverslip was preferablysecured to the land of the rigid body by an ultrasonic weld.

The Sell et al U.S. Pat. No. 4,567,149 device is widely accepted andstill in successful use. In use, the support and threads are filled andincubated with a liquid specimen, such as human sera. A secondaryantibody (for example antibody conjugated to horse radishperoxidase—which reacts with luminol)—is incubated for about four hours.Thereafter, the threads were washed with a buffer—a saline solution anddrained. This washing occurred three times. After this step, a fluid,which induces a chemiluminescent reaction, is introduced. The amount ofmultiple biological agents interacting with the binding assay componentscoated on the threads is determined by noting the presence and absenceof light being emitted from each of the wells. For example, whenscreening for the presence of multiple allergen-specific IgE classantibodies in a liquid sample, the device is incubated with the testsample and then, after washing, incubated with a solution containinglabeled antibodies against the IgE class antibodies that have bound tothe threads. The threads are then analyzed to determine the presence ofthe labeled antibodies. If the labeled antibodies are labeled with aradioactive tracer, such as ¹²⁵I, this analysis can be accomplishedusing a gamma counter. Alternatively, the analysis can be accomplishedby placing the threads adjacent to photographic film for exposure and bythen measuring the degree of exposure or more recently by registrationto a light detector, either fiber optic or by direct detection.

This device has experienced a high degree of commercial success. Thisdisclosure is an improvement on that device. Specifically, we haveundertaken a systematic and extensive analysis of this prior art device.In what follows, the reader will have enumerated the specific areas forimprovement.

It is to be understood that we claim invention in both determining thefollowing areas for improvement as well as the specific solutions, whichwe have adopted in this disclosure. It is well understood that theidentification of issues to be resolved, as well as their solution, canconstitute invention. Therefore, in so far as the prior art has notidentified the issues we now enumerate, with the device of Sell et alU.S. Pat. No. 4,567,149, invention is claimed.

DISCOVERIES

First, Sell et al U.S. Pat. No. 4,567,149 device had an elongate shallowwell or channel which was uniform in cross-section, only interrupted bythe threads that crossed the chamber. This resulted in a device, whichrequired approximately 1.5 milliliters of serum to produce the desiredtest result. Unfortunately, pediatric samples in most cases are of alesser volume. For example, it was determined that a device requiring0.500 milliliters or less would have greater utility, especially in thepediatric field.

Secondly, it has been determined that threads in general, and especiallycotton threads, require large volumes of allergen/antigen/reactant intheir absorption. For example, 40 milliliters of allergen extract wasrequired to coat 12 yards of thread which could be used as one of 600threads in the units of the device of Sell et al U.S. Pat. No.4,567,149. This rate of usage increases the cost of the test, as itrequires very large-scale allergen extraction. This is a disadvantagebecause it increases the cost of the product. Additionally, the threadis a natural product (cotton) and it can be difficult and costly tocontrol in quality from lot to lot.

As will hereafter be disclosed, this same 40 milliliters of allergen maynow be used for 20,000 tests!The new design has allergens directlyattached to the polystyrene coverslip and no thread is used.

Third, the alignment and registry of the individual threads between inthe individual lands of the device required constant attention andeffort. Misalignment had to be avoided to prevent “false positive” or“false negative” reactions.

Fourth, and once the threads have been incubated with reactants—such asserum—it is required that they be washed and drained. With a straightflow path, washing of threads requires excessive fluid. Further, cottonthreads utilized provided both resistance to uniform washing as well asencouraging fluid retention of the human sera or saline solution.Specifically, at the juncture of the threads and flow path, residualsolution—either the sera or the saline solution—tended to accumulate.This accumulation occurred due to the combination of surface tensioncombined with the irregular surfaces provided where the threads enteredthe channel of the device. Specifically, the cotton threads introducedadditional salient features (surfaces) where fluid could be entrapped bysurface tension (capillary forces). The operator is currently expellingthis fluid manually.

The device is currently used for in vitro testing of immune reactions tovarious allergens. From a fluid mechanics prospective, the operation ofthe device requires that blood serum be aspirated into the test chamberwhere it comes in contact with the various allergens deposited into thethreads. The serum is subsequently drained (under gravity) from the testchamber and a saline solution is used to further wash the device. Duringthe washing cycle, a nozzle is inserted into the inlet atop the device,forming a hermetic seal that enables fluid to be injected under pressureinto the test chamber. When this seal is broken by the removal of thenozzle, the resulting pressure vacuum is alleviated, which allows thefluid to drain from the device. The incomplete or even inconsistentdraining of the washing solution from the test chamber represents apotential dilution problem for the subsequent operation of the device,requiring the operator to ensure that all fluid is expelled from thechamber after washing.

Fifth, the light output from the device indicating a reaction could beimproved upon. Specifically, threads exhibiting a very high reactioncould radiate light outside of its readable area, necessitating the useof a quenching reagent. Further and where a reaction was extraordinarilyweak, an increase in substrate was needed.

Sixth, the coverslip is made of extruded polystyrene, which is prone toscratches and is difficult to manufacture necessitating QA efforts toselect parts. Even though the scratches are only cosmetic defects, amolded part would eliminate them and be more cost effective.

In short, our detailed study made clear that improvement was possible.

SUMMARY OF THE INVENTION

An enclosed chamber is used in a system for screening of a liquidspecimen through binding assays. The enclosed chamber includes an inlet,an outlet, and a plurality of discrete reactant containing wellscommunicated by a common reagent flow path between the inlet and theoutlet. A transparent member or coverslip defines on an inside thereofthe plurality of wells. Each well has a bottom for receiving a reactant,which emits light upon reacting. The coverslip further defines betweenthe bottom of the plurality of wells and the exterior of the coverslip alight path for detection of the reaction. This coverslip can optionallydefine at least one lens at each well and is a molded part. This lightpath re-emits light from reactions within the well to the exterior ofthe coverslip indicating the absence of or presence of a reaction. Abottom member defines for each of the plurality of wells aflow-diverting member. The flow-diverting member is a continuoussurface, the continuous surface protruding to and toward one of theplurality of wells for deflecting fluid flowing from the inlet to theoutlet into the interior of the wells. This deflection permits washingof fluids from the plurality of wells. At the same time, the continuoussurface enhances and substantially improves fluid draining of theflushing solution—usually a saline solution. Where a solution havingeither the emission or absence of light is utilized to indicatereaction, the light path and optional lenses serve both to concentratethe light emitted as well as to inhibit false positive indications.Finally, an opaque partition with slits is disclosed for surrounding theindividual lenses and generally isolating the light path from each well.Improved detection results.

With the assembly of a coverslip, a bottom member and an opaquepartition, a chamber that uses a low volume of patient serum results.The present chamber is filled by approximately 270 μl of liquid. Thechamber is especially useful in the case of pediatric samples. At thesame time, the reduction in volume does not result in poor washingcharacteristics. The fluidic design of the chamber allows for the use ofsmall volumes of patient sera as well as insures sufficient washing.

The internal test chamber with its flow augmentation features has beendesigned, based on Fluid Mechanics principles, to optimize the washingof the allergen wells and the draining characteristics of the device.The shape, size, and placement of (a) the allergen cavities, (b) theflow augmenting “continuous surface”, and (c) the chamber inlet/outletsections have been selected to: (1) minimize the internal volume of thetest chamber, (2) reduce capillary fluid retention during draining, (3)maintain optimal washing of the allergen cavities at low and high flowrates, and, (4) allow for the efficient operation of the device over awider range of positions.

The contoured “continuous surface” enhances the washability of thedevice by re-directing the main channel flow into the allergen cavities.The device may be operated without significant loss in washing/drainingefficiency up to 35 degrees offset from the nominal vertical position.

The migration from the flat coverslip toward the new allergen wellsintroduced new complexities into the design. Where draining was one ofthe major issues with the flat coverslip configuration, here the“wash-ability” of the device in the presence of the allergen cavitiesbecomes the major area of concern. That is, the ability of the flowpattern induced by the injection of the washing solution into thechamber to displace the more viscous reagent or blood serum from thesurfaces and corners of the allergen cavities. Thus, the internal shapeof the test chamber is designed to allow for sufficiently strong fluidflow to penetrate into these cavities and clean them out.

Strictly from a fluid mechanics prospective, it is desirable to havethese cavities be as wide as possible in the direction of the flow andalso as shallow as possible. However, the cavities must be sufficientlydeep to allow for the deposit of the required amount of material to betested, such as the allergen. Furthermore, the cavities cannot be madeexcessively wide without an adverse effect on the optics of the device,i.e. the ability of the light path and partition system (with or withoutthe optional lens) to efficiently concentrate the light for detectionand to isolate the emitted light from the adjacent wells. Therefore, thedesign of the allergen cavities has been carried out in a manner thatsatisfies the flow, optical, and chemical requirements of the device.

One of the changes needed was to design a chamber that could focus thelight output. This change in design is important for three reasons.Firstly, the new chamber is designed to increase assay specificity whenvery high patient response is experienced. Secondly, the chamber isdesigned to increase assay sensitivity by focussing the light onto thedetector system. Third, the light is no longer emitted from a linesource such as thread. It is instead emitted from the flat bottomsurface of a well.

From an optical perspective, the design goal is to develop an in vitrodiagnostic test chamber that will allow the light emitted by multipleallergens placed within a chamber to be efficiently collected whileobtaining minimum light cross-over between these multiple allergens. Thedetection system that detects the light emission operates (as byscanning) along a line collecting light that enters its input aperturewithin a given angular range. In a detection device utilizing the priorart heretofore described, positioning the detection optic (it actuallyreads it as it scans past) collects the light from a single allergen ata particular location along its scan line. Essentially, because of therequirement to be backward compatible with the existing detectionequipment, some of the chamber geometry is fixed. Two pieces, anoptically absorbent main body and the optically transparent coverslipform the chamber.

The allergen is placed in spaced wells (which may or may not be equallyspaced) directly onto the transparent coverslip. Typically the surfaceof the well where the allergen is placed can be treated by radiation,such as gamma or ultra violet. The depth of the wells and the shape ofthe tapered edges are determined as a tradeoff to minimize the lightcross-over and maximize the washing capabilities. The top of thecoverslip has a series of indentations between each of the wells that donot extend entirely through the piece. On the top of the coverslip is anoptically opaque partition piece which has slots located directly aboveeach allergen well. These slots allow light to pass through the lensesto the detector. The partition piece has fingers or individual opaquepartitions with slits that extend into the indentations in the coverslipto block light from passing to the adjacent read area.

On top of the coverslip, directly above the wells that hold theallergens, is a series of equally spaced lenses. The lenses protrudeinto the slots in the partition and can have various shapes. By properlytailoring the curvature of the lenses the amount of light from eachallergen that is collected and detected by the detection system can beoptimized. This invention allows the lenses to have a cylindrical shape,a toroidal shape, or spherical surface profile to optimize the lightcollection efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side elevation section of the assembled in vitro diagnostictest chamber illustrating from bottom to top, the lower test chamberbody, the common reagent volume; the upper coverslip defining theindividual wells and lenses; and the overlying optical partition;

FIG. 1B is a side elevation section of the assembled in vitro diagnostictest chamber illustrating from bottom to top, the lower test chamberbody, the common reagent volume; the upper transparent member definingthe individual wells, light path without lenses; and the overlyingoptical partition;

FIG. 2 is an enlarged diagrammatic representation of the action of theflow path deflecting a flushing flow interior of a well within thetransparent coverslip;

FIG. 3A is a perspective view of the bottom chamber member defining thecontinuous curvilinear protrusion between the inlet and outlet of thechamber of this invention;

FIG. 3Bis a perspective view of the coverslip from the well side, itbeing realized that for assembly to occur rotation of the coverslip by180° is required to occur;

FIG. 3C is a perspective view of the optical partition for overlying theindividual lenses of each of the diagnostic wells;

FIG. 4A is a bottom plan view of the bottom of the chamber body;

FIG. 4B is a side elevation section of the bottom of the chamber body;

FIG. 4C is a top plan view of the interior of the chamber body;

FIG. 4D is an end elevation section of the entrance to the chamber inthe bottom of the chamber body;

FIG. 4E is a top plan view of the entrance in the bottom of the chamberbody;

FIG. 5A is a top plan of the coverslip incorporating cylindrical lenses;

FIG. 5B is a side elevation of the coverslip illustrating the sideelevation of the lenses;

FIG. 5C is a bottom plan of the plate of FIG. 5A;

FIG. 5D is a top plan of the coverslip without lenses;

FIG. 5E is a side elevation of the coverslip without lenses;

FIG. 5F is a bottom plan of the coverslip without lenses;

FIG. 6A is a bottom plan of the optical partition of the chamber;

FIG. 6B is a side elevation section of the optical partition of thechamber body;

FIG. 6C is a top plan of the optical partition of the chamber body; and,

FIG. 6D is an enlarged side elevation section taken at the opticalpartition.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

Referring to the side elevation section of FIG. 1A, an overallunderstanding of the assembled chamber C can be attained. Chamber Cincludes bottom B defining flow protrusions P. As will hereafter be setforth, it is the function of bottom B and flow protrusions P to providean efficient cleansing action to the individual wells W containing thedesired reactants R To aid in minimizing light carry-over, bottom B ismade from a material, which absorbs light. We prefer the use of anopaque material that absorbs light as distinguished from materials,which in any way may be reflective.

Overlying bottom B and spaced apart from the bottom as shown in FIG. 1is transparent member or coverslip T. Coverslip T serves three majorfunctions. First and when inverted from the disposition shown in FIG. 1Aand 1B, individual wells W receive reactants R. Reactants R adhere tothe bottom of wells W when coverslip T is inverted. (See FIG. 2).

Second, transparent cover or coverslip T permits light to escape fromreactants R in wells W when a diagnostic process is completed. Takingthe example of a screen test for allergy, one or more of the wells W mayemit light indicating the presence or absence of a specific type ofallergic reaction.

Third, coverslip T defines lenses L in FIG. 1A, only. These lenses L aretypically cylindrical, overly wells W and permit a generally collimatedlight beam B to escape from reactants R at the completion of adiagnostic reaction. In FIG. 1B, an embodiment is shown which does notinclude lenses L.

Finally, and fitting around lenses L, opaque piece S is shown. Opaquepiece S includes opaque partition with slits 14 that protrude on eitherside of the individual lenses L. It is the function of opaque partitionwith slits 14 to limit light from reactants R in one well W from givinga “false positive” indication. This can occur by the light escaping fromone well to a lens L overlying an adjacent well W. The purpose of theopaque piece S is also to minimize the light that is emitted laterallyfrom one well to intersect and then scatter from an adjacent well.

Referring to the side-by-side perspectives of FIGS. 3A, 3B and 3C andwith special attention to FIG. 3B, assembly of the diagnostic chamber ofthis invention can be easily understood. FIG. 3B illustrates coverslip Tfrom the side containing the individual wells W. It begins with well W1and ends with well W38. In the example here shown, wells W1, W2, and W3have each been filled with a reagent R1, R2, and R3. In the normalcourse of events, coverslip T would be rotated 90° and have allthirty-eight wells filled, each one with a different reagent. Typically,each reagent would be treated until adherence to the bottom of wells Woccurred. In the usual case, this will only require drying undercontrolled conditions. Once this adherence has occurred, coverslip T isreversed from the position shown in FIG. 3B so that lenses L (not shown)are toward the viewer.

The rest of the assembly is conventional. Coverslip T is fitted tobottom B in fluid tight relation. Between coverslip T and bottom B, afluid tight volume is defined between inlet I and outlet O. Thereafter,opaque piece S is fitted over coverslip T at lenses L with opaquepartition with slits 14 disposed on each side of each lens L. Thereresults an assembled diagnostic test chamber C.

Use of chamber C can be outlined. In use, chamber C is filled throughinlet I with outlet O open until fully filled with reagent—which isusually serum for detecting an allergic reaction. When filled, reactantsR are incubated for a sufficient interval to indicate the presenceand/or absence of a reaction.

A secondary antibody (for example an antibody conjugated to horseradishperoxidase—which reacts with luminol)—is then incubated. Thereafter, thewells W are washed with a saline solution and drained. This washing anddraining utilizes flow protrusions P within the continuous reactant flowpath.

After this step, a fluid, which induces a chemiluminescent reaction, isintroduced, this chemiluminescent reaction occurs at wells W wherereactants R have a reaction. (See FIG. 2) The amount of multiplebiological agents interacting with the binding assay components coatedon the wells W is determined by noting the presence and/or absence oflight being emitted from each of the wells.

For example, when screening for the presence of multipleallergen-specific IgE class antibodies in a liquid sample, the device isincubated with the test sample and then, after washing, incubated with asolution containing labeled antibodies against the IgE class antibodiesthat have bound to the wells. The wells are then analyzed to determinethe presence of the labeled antibodies. If the labeled antibodies arelabeled with a radioactive tracer, such as ¹²⁵I, this analysis can beaccomplished using a gamma counter. Alternatively, the analysis can beaccomplished by placing the device adjacent to photographic film forexposure and by then measuring the degree of exposure or more recentlyby registration to a light detector, either fiber optic or by directdetection.

Having described the overall operation, attention may now be directed tothe flow dynamics and optics resulting from this disclosure.

The average shear stress, τ, along the cavity wall at the well bottomwas optimized. This shear stress represents a measure of the force thatthe washing solution would be capable of exerting on reagent or serumfluid particles that lie along the bottom of the wells W.

Referring to FIG. 2, computer models for alternative configurations wereconstructed and used to obtain the flow pattern with the test chamber.The preferred embodiment resulting from these tests is shown in FIG. 2.

The magnitude of the resulting shear stress, averaged along the cavitywall, was computed and normalized against the base case. In the absenceof any bumps on the bottom channel wall the “high-speed” main channelflow merely induces, as a result of shear (or friction) between thelayers, a flow within the cavity. This flow is typically much weakerthan the main channel flow. The most efficient flow, in terms of wallshear, occurs at an aspect (depth to width) ratio of approximately 0.5.If the cavity is too deep then the induced flow becomes too weak in thearea adjacent to the top cavity wall. If the cavity is too shallow, itprevents the establishment of a well-organized flow pattern and theresulting wall shear begins to drop (note the decrease in τ, as thecavity depth decreases.

The preferred design for the well/protrusion configuration can be seenin FIGS. 1A and 1B. FIG. 2 sets forth an actual flow model illustratingfluid flow through the cavity of FIG. 4. While, dimensions are normallynot important to invention, the design of the flow chamber here doeshave dimensional significance.

Referring to FIG. 1A and 1B, the depth of the flow channel is 0.011inches. The channel inclines at a 27.4° angle upward and downward. Thechannel varies in elevation 0.020 inches. When viewed in plan thechannel has an approximate width of 0.157 inches. The protrusion iscentered with respect to well W. Total volume to fill the flow cavity isin the range of 270 μl.

In short, the geometry of the selected configuration has been determinedbased on numerous iterations that allowed for the successive improvementof the design concept. The basic cavity shape was changed from arectangle to the top of a trapezoid.

Furthermore, the cavity walls better facilitate the draining of thedevice.

Assuming that a lens as set forth in FIG. 1A is used, optics throughlens L must deliver relative low quantities of light to any particulartest system used with the device. At the same time, light cross-overbetween a well W having reaction and an adjacent well not having areaction must be prevented. We have discovered that the combination ofthe cylindrical lenses L with the flat well bottom of wells W produces arelatively collimated output of light from reaction. By constructing thebottom B and the opaque piece S from plastic opaque and absorbent to thelight emitted (indicating the presence or absence of reaction), lightcross-over is minimized.

It will be understood that the disclosed optics in combination with thewell W represents a careful compromise that in large measure has beenempirically determined.

It has been emphasized that because of the relative small size andvolume of the device that dimension is important. Accordingly, weprovide the now preferred production drawings relating to the actualdevice as part of this disclosure. FIGS. 4A–4E illustrate the opaquebottom. FIGS. 5A–5C illustrate the coverslip T with cylindrical lensesincorporated to the design. FIGS. 6A–6D illustrate the opticalpartition. These are all provided so that the true dimensionality ofthis invention can be understood.

The reader should understand that we claim invention in at least twocombinations. First, the interaction of the wells with the discretelenses indicating the presence or the absence of a reaction within thediscrete wells constitutes one portion of this invention. Secondly, theinteraction of the wells within the continuous path constitutes anotherportion of this invention. For example, in certain protocols, it may bepossible to open the device and expose the wells directly for theemission of light In this case, the interaction of the protuberanceswith the wells to assure a minimal volume of serum to promote theoriginal reaction would constitute our invention.

We contemplate the use of all different kinds of labels for detectedreactions. While we have enumerated ¹²⁵I and chemiluminescent reactions,other forms of labels will do as well. For example, color metricenhanced reactions can be used. Further, while we set forth as ourprimary utility an allergic reaction, other types of reactions can beused as well. These other types of reaction can include detection ofcancer markers, infectious diseases, hormones, autoimmune, and drugabuse.

1. In an enclosed chamber for use in a system for screening of a liquidspecimen through binding assays, the enclosed chamber including aninlet, an outlet, and a plurality of discrete reactant containingregions communicated by a common reagent flow path from the inlet to theoutlet, the apparatus comprising: a transparent member defining on aninside thereof a plurality of wells each having a bottom for receiving areactant which emits light upon reacting; the transparent member furtherdefining between the bottom of the plurality of wells and the exteriorof the transparent member at least one lens at each well for emittinglight from reactions within the well to the exterior of the transparentmember; a bottom for enclosing the plurality of wells and definingbetween the inlet and the outlet a flow path connecting the plurality ofwells into the common reagent flow path between the inlet and theoutlet; the bottom defining for each of the plurality of wells a flowdiverting member defining a continuous surface, the continuous surfaceprotruding to and toward one of the plurality of wells for deflectingfluid flowing from the inlet to the outlet into an interior of theplurality of wells for permitting washing of fluids from the pluralityof wells.
 2. The enclosed chamber for use in a system for screening of aliquid specimen through binding assays according to claim 1 and furthercomprising: each of the plurality of wells includes a planar bottom overthe chamber bottom.
 3. The enclosed chamber for use in a system forscreening of a liquid specimen through binding assays according to claim1 and further comprising: each of the plurality of wells includes wellsides defining obtuse angles to and toward the common reagent flow pathfrom the inlet to the outlet.
 4. The enclosed chamber for use in asystem for screening of a liquid specimen through binding assaysaccording to claim 1 and further comprising: each of the wells containsa coating from the group consisting of an allergens an antigen or areactant.
 5. The enclosed chamber for use in a system for screening of aliquid specimen through binding assays according to claim 1 and furthercomprising: a member defining optically opaque boundaries between thelenses for the wells to prevent light emitted from one reaction in onewell from being transmitted to lens overlying a different well.
 6. Theenclosed chamber for use in a system for screening of a liquid specimenthrough binding assays according to claim 1 and further comprising: thecommon reagent flow path from the inlet to the outlet serially connectsthe plurality of wells.
 7. In an enclosed chamber for use in a systemfor screening of a liquid specimen through binding assays, the enclosedchamber including an inlet, an outlet, and a plurality of discretereactant containing regions communicated by a common reagent flow pathfrom the inlet to the outlet, the apparatus comprising: a memberdefining on an inside thereof a plurality of wells each having a bottomfor receiving a reactant; a bottom for enclosing the plurality of wellsand defining between the inlet and the outlet a flow path connecting theplurality of wells into the common reagent flow path between the inletand the outlet; and, the bottom defining for each of the plurality ofwells a flow diverting member defining a continuous surface, thecontinuous surface protruding to and toward one of the plurality ofwells for deflecting fluid flowing from the inlet to the outlet into aninterior of the plurality of wells for permitting washing of fluids fromthe plurality of wells.
 8. The enclosed chamber for use in a system forscreening of a liquid specimen through binding assays according to claim7 and further comprising: the depth of the well from the top of surfaceis 0.2 inches.
 9. The enclosed chamber for use in a system for screeningof a liquid specimen through binding assays according to claim 7 andfurther comprising: the common reagent flow path contains less than 300microliters.
 10. The enclosed chamber for use in a system for screeningof a liquid specimen through binding assays according to claim 7 andfurther comprising: the flow-diverting member is centered with respectto the well.
 11. The enclosed chamber for use in a system for screeningof a liquid specimen through binding assays according to claim 7 andfurther comprising: the wells are treated with radiation at the well forretention of allergen/antigen/reactant placed in the well.
 12. Theenclosed chamber for use in a system for screening of a liquid specimenthrough binding assays according to claim 7 and further comprising: themember defining on an inside thereof a plurality of wells istransparent.
 13. The enclosed chamber for use in a system for screeningof a liquid specimen through binding assays according to claim 7 andfurther comprising: the member defining on an inside thereof a pluralityof wells defines a lens overlying each of the wells for emitting lightresponsive to light being emitted from a reactant in the wells.
 14. Theenclosed chamber for use in a system for screening of a liquid specimenthrough binding assays according to claim 7 and further comprising: eachof the plurality of wells includes a planar bottom.
 15. The enclosedchamber for use in a system for screening of a liquid specimen throughbinding assays according to claim 7 and further comprising: each of theplurality of wells includes well sides defining obtuse angles to andtoward the common reagent flow path from the inlet to the outlet. 16.The enclosed chamber for use in a system for screening of a liquidspecimen through binding assays according to claim 7 and furthercomprising: each of the wells contains a coated substance chosen fromthe group consisting of an allergen, an antigen and a reactant.
 17. Theenclosed chamber for use in a system for screening of a liquid specimenthrough binding assays according to claim 7 and further comprising: thecommon reagent flow path from the inlet to the outlet serially connectsthe plurality of wells.
 18. A process of screening of a liquid specimenthrough a series of binding assays between the inlet and outlet of anenclosed chamber; the process comprising the steps of: providing atransparent member defining on an inside thereof a plurality of wellseach having a bottom for receiving a reactant which emits light uponreacting; depositing and adhering different reactants in differentwells; providing at least one lens at each well for emitting light fromreactions within the well to the exterior of the transparent member;providing a bottom for enclosing the plurality of wells and defining theinlet, the outlet, and a flow path between the inlet and the outletconnecting the plurality of wells into the common reagent flow path;passing a reactant fluid from the inlet to the outlet to flood thecommon reagent flow path and react with reactants in the plurality ofwells; washing the reactant fluid from the wells by passing washingfluid from the inlet to the outlet over the continuous surfaces toenable washing of reagent from reactants in the plurality of individualwells; and, passing a reaction indicator through the enclosed passagefrom inlet to outlet, the reactant indicator having a luminescentreaction to indicate the presence and/or absence of reaction between thereactant and the reagent in the well.
 19. A process of screening of aliquid specimen through a series of binding assays between the inlet andoutlet of an enclosed chamber according to claim 18; the processcomprising the further steps of: defining for each of the plurality ofwells a flow diverting member defining a continuous surface, thecontinuous surface protruding to and toward one of the plurality ofwells for deflecting fluid flowing from the inlet to the outlet into aninterior of the plurality of wells for permitting fluids to contactreactants within the wells.